Thousands took to the streets in cities across Morocco on Sunday demanding better civil rights and an end to corruption in the moderate North African country where the king this month promised constitutional reform.

"Morocco should start drawing some serious lessons from what's happening around it," said Bouchta Moussaif, who was among at least two thousand people marching alongside the city's medieval walls in the capital Rabat.

Thousands joined protests in Morocco's main city, Casablanca, in Tangiers in the north, and in Agadir on the Atlantic coast where witness Hafsa Oubou said several thousands were marching.

A government official said at least as many were protesting as on Feb. 20 when interior ministry estimates were 37,000.

Unrest has swept across North Africa since December, toppling regimes in Tunisia and Egypt, prompting international military intervention against Libya, and protests in Algeria.

"The king did not meet the demands made during the first nationwide protest, that's why we are here again. He promised to reform the constitution and we all know how far those promises have got us," Moussaif said.

Morocco's King Mohamed promised on March 9 to reform the judiciary, create a stronger role for parliament and political parties and boost the authority of local officials, and appointed a committee to work with political parties, trade unions and civil society groups to draw up proposals by June.

"The Moroccan people want something that goes beyond the king's speech," said Abdelhamid Amine of AMDH human rights group. "They want their society to cease being one of subjects and become a society of citizenship."

Added Moncef Haddari, 82, said: "We will demonstrate until we get a new constitution chosen by the people."

Many women, some with hijab fully covering their faces, carried pictures of relatives jailed in the wake of a security crackdown that saw thousands of people sentenced to often long prison terms after 12 suicide bombers killed 33 people in Casablanca in 2003.

"My son has been on death row for seven years now. They have sentenced him to death because he prays. Death for being a good Muslim," said Zahra Sahif, who carried a pink prison visit card with both her picture and her son's.

"They did not even give him the chance for an appeal," she continued. "What kind of justice is this? Is it because the Americans give them money?"

King Mohamed VI succeeded his father in 1999 and holds ultimate power in the country of 32.6 million. Some in the crowd carried his picture and said they wanted changes under which the country would remain a kingdom.

"We all are for our king. But I agree that the prime minister and the king's two aides should get out," said protester Dalila, referring to Prime Minister Abbas El Fassi, Mohamed Mounir El-Majidi, the king's secretary who has made a fortune from billboard advertising and Fouad Ali Himma, a classmate of the king and former deputy interior minister.

"We want an end to the corruption you find everywhere," said Dalila, a woman dressed in Western clothes.

Some protesters carried brooms as they chanted "We want an end to corruption". A few people carried cardboard "F"s, a reference to the Internet site Facebook which has played an important role in helping organising anti-government protests.

The Socialists' USFP party announced late on Saturday that it would join the protest - the first government coalition party to do so.

Morocco was seen as less likely to face public protests than other countries in North Africa and the Middle East, but calls for change have intensified as people sense a rare opportunity.